ASTM D6780_D6780M-19 - Standard Test Methods for Water Content and Density of Soil In situ by Time Domain Reflectometry (TDR)
Standard Test Methods for Water Content and Density of Soil In situ by Time Domain Reflectometry (TDR)
| Standard number: | ASTM D6780_D6780M-19 |
| Released: | 01.08.2019 |
| Status: | Active |
| Pages: | 17 |
| Section: | 04.09 |
| Keywords: | compaction test; construction control; density; dielectric constant; electrical permittivity; electromagnetic waves; field control; field tests; inspection; moisture content; quality control; soil compaction; soil density; time domain reflectometry; water content; |
1.1 This test method may be used to determine the water content of soils and the density of soils in place using Time Domain Reflectometry.
1.2 This test method applies to soils that have 30 % or less by weight of their particles retained on the 19.0-mm [3/4-in.] sieve.
1.3 This test method is suitable for use as a means of acceptance for compacted fill or embankments.
1.4 This test method is not appropriate for frozen soils or soils at temperatures over 40°C [100°F] and may not be suitable for organic soils, highly plastic soils, or extremely dense soils.
1.5 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.
1.5.1 The method used to specify how data are collected, calculated, or recorded in this standard is not directly related to the accuracy to which the data can be applied in design or other uses, or both. How one applies the results obtained using this standard is beyond its scope.2
1.6 Two alternative procedures are provided to determine the water content and the density of soil in situ:
1.6.1 Procedure A
involves two tests in the field, an in situ test and a test in a mold containing material excavated from the in situ test location. The apparent dielectric constant is determined in both tests.
1.6.2 Procedure B
involves only an in situ test by incorporating the first voltage drop and long term voltage (V1 and Vf ) in addition to the apparent dielectric constant. While the bulk electrical conductivity can be determined from these measurements, it is not needed for the determination of water content and density.
1.7 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. For additional information consult SI10.
1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.